Oxidation Behavior of CVD and Single Crystal SiC at 1100°C

Abstract

High purity chemical vapor deposition (CVD) silicon carbide fabricated by a commercial process was examined and oxidized at 1100~ along with high purity single crystal silicon carbide. The freestanding CVD thick films had a highly textured polycrystalline microstructure, with the <111 > directions of the crys_tals_parallel to the growth direction. This texturing maintained the polarity_of the 43m crystal structure, implying that either the [111 ] or the [1 ! 1] direction grew significantly faster during the CVD process. The (1 1 1 ) face of the cubic, CVD-SiC oxidized at the same rate as the (0001) face of the single crystal SiC. The (111 ) face of the CVD-SiC oxidized at nominally the same rate as the (0001) face of the single crystal SiC.

Growth of SiO2on SiC by dry thermal oxidation: mechanisms

“…Since the oxidation rate has been shown to depend only weakly on the polytype for the Si-face and not at all for the C-face [17], we find it reasonable to assume that although there may be small quantitative differences between the oxidation processes of different polytypes along the perpendicular directions to the bilayer stacking units, the main processes-diffusion, interface reaction rates and so on, should be largely comparable, and so it is reasonable to discuss oxidations mechanisms without paying special attention to the polytype. Nevertheless some early oxidation experiments were performed before the wide availability of good quality substrates, for example, using hotpressed powders [18] or textured polycrystalline layers [19]. We therefore restrict our attention here to experiments in which the oxidation conditions and the nature and orientation of the single crystalline substrate are clearly defined.…”

High Temperature Passive Oxidation Mechanism of CVD SiC

“…Fig. 5 summarizes the kp values in O 2 atmospheres for pure materials of CVD and single crystal SiC bodies [13][14][15][16][17][18][19]. It is generally understood that the activation energy can be a relatively small value around 100 kJ/mol below 1600 K implying the oxygen permeation limited process [6].…”

Carbon Interlayer Between CVD SiC and SiO2in High‐Temperature Passive Oxidation

“…The oxidation behavior of SiC has been studied in a wide temperature range and at various atmospheres. 1, In particular, several studies have been devoted to understand the oxidation kinetics in sintered SiC, [6][7][8][9] highly pure chemical vapor deposited (CVD) SiC, [10][11][12][13][14][15][16][17][18][19][20][21][22][23] and single crystalline SiC. 7,8,[25][26][27] Among them, sintered SiC usually contains additives such as boron, carbon, and aluminum, which tend to degrade its oxidation resistance at high temperatures.…”